The purpose of this paper is to describe temporal trends in the treatment of lung cancer in the Merseyside Region of England over the years 1974-86. A detailed analysis of 9,090 cases of histologically confirmed tumours showed that age at diagnosis and histological type were important prognostic factors, with the 5 year survival of adenocarcinoma, squamous carcinoma, undifferentiated carcinoma and small cell carcinoma after treatment being 22.5%, 18.5%, 10% and 3.5% respectively. An analysis of 741 cases of small cell carcinoma given chemotherapy over the same period showed progressive improvement in 2 year survival from 2.5 to 7.5% (P less than 0.001) and this was shown to be closely associated with the increasing use of intravenous combination chemotherapy. The survival of patients who underwent surgical resection in the three periods 1974-77, 1978-81 and 1982-86 showed a continuous improvement in median survival from 13 to 30 months (P less than 0.001). Overall survival curves of all treated cases showed a significant improvement in median survival from 8 to 10 months and 5 year survival from 12.5 to 17.5% (P = 0.001). With improved staging assessment, the value of surgical resection of all histological types is emphasised, and in the case of the small cell subtype, the increasing use of combination chemotherapy would appear to have paralleled an increase in median and 2 year survival. These data support the argument that with appropriate case selection, there is a survival benefit associated with active treatment for lung cancer.